I'm with 250Kts on this one - a question I have asked from day one.
However Zooker you might have hit upon something (at least Barron might thinks so as he seems to believe we can get trainees to do the course for nothing, he believes we could be like the pilot training pipeline where everyone pays to train).
Taking your argument one step further... as we are in the top 20 big companies (by the skin of our teeth), we could ask applicants to offset any bond with a large wad of dosh.
Lets say they pay for their training, but because we are in the top 20, on top of that they then have to stay for 5 years after they complete the training (they have paid for). If they want to leave early, to work for SERCO for instance (

), they pay £10k for every year they leave before the 5 is up.
All monies received go into the OJTI payment pot.